Scientists develop indigenous ‘Chip-Off’ technique to retrieve encrypted data

Using the technique, data has been retrieved from a smart cell phone which had been locked with the finger prints of a person who had died by suicide.

The technique is divided in six parts including opening the device using heat and air combination to remove its back and front covers, battery screws, other connections, etc. to retrieve the motherboard, the NAND flash memory is located on the retrieved motherboard/circuit board, using appropriate heat (disordering) and chemicals (adhesive removal), the memory chip is physically removed. The removed chip is cleaned and/or reballed if necessary and the forensic image/dump of the chip is then acquired by using an imaging software and an adapter connecting it to the PC. The further analysis is conducted with the standard softwares at the laboratory.

Dr SK Jain, Director CFSL-36, said, “After CFSL, Hyderabad, CFSL-36, Chandigarh, is becoming the second laboratory in the country for retrieving data from the locked and damaged smart cell phones in India. The technique was developed in the laboratory in December 2020. Now, we have started using the technique here. Indeed, the technique is being used in developed countries like the US for a long time, but these countries do not share the technology with us. However, the limitations of this method are observed when the mobile device received are of higher Android or IOS versions including Apple iphones. The only data extracted from such mobile devices by chip-off method are found in an encrypted condition and methods of decryption are still under development. The technique can be used only with the due permission of the competent court.”

Difficulties in Chip-off technique

• Locating NAND flash memory of the exhibit from its motherboard.
• Setting optimum hot airgun temperature so that chip can be plucked easily.
• Cleaning of the chip after successfully disordering it from its motherboard.
• Locating pinpoints for reading the chip and choosing suitable adapters for it.